tools: sync uapi/linux/bpf.h

Pull changes from "bpf: respect size hint to BPF_PROG_TEST_RUN if present".
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/include/uapi/linux/bpf.h

@@ -374,8 +374,11 @@ union bpf_attr {
 	struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
 		__u32		prog_fd;
 		__u32		retval;
-		__u32		data_size_in;
-		__u32		data_size_out;
+		__u32		data_size_in;	/* input: len of data_in */
+		__u32		data_size_out;	/* input/output: len of data_out
+						 *   returns ENOSPC if data_out
+						 *   is too small.
+						 */
 		__aligned_u64	data_in;
 		__aligned_u64	data_out;
 		__u32		repeat;